Max level
There is no hard cap on leveling up. I am usually about level 17 or so at the end of the game.

End game character?
I'm not sure what you mean by this. You can play a pretty virtuous type character if you wish, but you will still be doing in lots of bad guys along the way.

Weight and magic
You have to increase your strength to be able to wear heavy armour . Obviously if you are putting points into strength you are neglecting the intelligence required for casting magic. The balance you strike is your choice.